Component Insulation from Vacuum Chamber

For posts specifically relating to fusor design, construction, and operation.
Post Reply
Conner Ruhl
Posts: 40
Joined: Wed Aug 08, 2012 2:52 pm
Real name:

Component Insulation from Vacuum Chamber

Post by Conner Ruhl »

Excuse my niavety, but why are some components (vacuum pumps, gauges, gas lines) insulated on some images of fusors I have seen, but not on others?
User avatar
Richard Hull
Moderator
Posts: 14992
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Component Insulation from Vacuum Chamber

Post by Richard Hull »

Insulation is not normally required on anything attached to the fusor except the HV terminal input line or anything associated with the inner grid (cathode). The fusor shell or body must be at ground potential. Any insulation is accidental or, if deliberate, is not necessary.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Conner Ruhl
Posts: 40
Joined: Wed Aug 08, 2012 2:52 pm
Real name:

Re: Component Insulation from Vacuum Chamber

Post by Conner Ruhl »

That makes sense, but what about a turbo pump? It seems like that may cause a problem. Maybe I am mistaking what is just an extension for insulation.
User avatar
Chris Bradley
Posts: 2930
Joined: Fri May 02, 2008 7:05 am
Real name:

Re: Component Insulation from Vacuum Chamber

Post by Chris Bradley »

Do you want to point to which images of kit you think shows insulated/uninsulated components? Usually, the interconnections between the parts are metallic, and everything ends up grounded one way or the other. I've not seen anyone here use plastic screws!?
Conner Ruhl
Posts: 40
Joined: Wed Aug 08, 2012 2:52 pm
Real name:

Re: Component Insulation from Vacuum Chamber

Post by Conner Ruhl »

I don't know if I can find them again, they popped up during an obscure google image search for some part I was looking at. I know I saw this though: http://www.lesker.com/newweb/feedthroug ... 8V2376.jpg
User avatar
Chris Bradley
Posts: 2930
Joined: Fri May 02, 2008 7:05 am
Real name:

Re: Component Insulation from Vacuum Chamber

Post by Chris Bradley »

If you want an electrically isolated chamber, then you can definitely make an isolated chamber if you want! My first design was glass and tufnol (bakelite) because I specifically wanted 'insulated', but it is still dead tricky to manage that scenario because you will still get discharges down your vacuum lines (to your grounded vacuum kit), unless you are really careful to control the 'pressure x distance' thing.

Other than that 'non-fusor' oddity - and also Steven Sesselmann's accelerator column with an end-chamber held to a big low potential - I don't recall seeing any examples of electrically isolated/ungrounded fusor chambers here.
Conner Ruhl
Posts: 40
Joined: Wed Aug 08, 2012 2:52 pm
Real name:

Re: Component Insulation from Vacuum Chamber

Post by Conner Ruhl »

O.K., thanks. I think that settles it.
Post Reply

Return to “Fusor Construction & Operation (& FAQs)”